Chemical agents are used as detergents, disinfectants, food additives, medicinal agents, etc. Use of these agents is often tied to the concentration of the chemical agent in a solution, i.e., the required concentration of the agent needed to accomplish the target use. It is therefore important to both measure and control the concentration of an agent in a solution during its use. For example, biocides are used to disinfect surfaces in the food and beverage industry, i.e., used in the cleaning and disinfecting of food surfaces, such as fruits and vegetables, food contact surfaces, such as counter tops and dishware, and in the cleaning and disinfecting of the inside surfaces of polyethylene telephthalate (PET) bottles. It is critical that a biocide be delivered to the target at a proper use concentration. Delivery of an insufficient amount of biocide may result in the target being tainted with possible hazardous levels of microbes and/or may result in the user violating certain predetermined regulatory requirements, causing the user to be fined or suspended by the relevant regulatory agency. Alternatively, delivery of an excessive amount of a biocide to a target may have a toxic effect on the field worker and/or consumer of the treated product, i.e., from fumes, skin contact or consumption. Further, excessive levels of biocide add unnecessary cost to the disinfection process, i.e., the biocide costs money, and a higher than necessary concentration of biocide may result in increased corrosion to delivery equipment thereby reducing the equipment's life expediency and potentially increasing maintenance costs. Therefore, it is of great importance to accurately monitor and determine the concentration of a chemical agent being delivered to a target over the time period of its target use, and to have the ability to modify the agent's concentration during that same time period.
One common technique for determining the concentration of a chemical agent in a solution is through the use of a manual titration kit. Here, a field worker manually takes a sampling of the solution having the target chemical agent that is being tested, adds an indicator agent to the sample and then adds titrant in a drop wise fashion until the approximate endpoint of the chemical reaction has been reached (the endpoint being a detectable point at which the concentration of the chemical agent is determined from the amount of titrant added, as discussed in greater detail below). The manual titration process tends to be fairly inaccurate because the amounts of sample solution, indicator agent and titrant can vary significantly with manual delivery, and the detection of the endpoint can vary significantly with manual detection. As a result, manual titration of a chemical agent's concentration of any two identical solution samples may vary as much as 20 to 50% by a typical worker in the plant. This variation in results is often unacceptable, as it continues to leave a large amount of uncertainty with regard to the target chemical agent's true concentration.
Furthermore, manual detection is labor intensive and time consuming. On average, a field worker may test a solution every hour or two, requiring the field worker to travel to and perform the titration. In addition, it is difficult to ensure a constant concentration or control of chemical if it is being measured and tracked only every 1 to 2 hours.
A recent attempt has been made to automate the processes used to detect chemical agents in a solution. A syringe mixing device draws a sample from the solution into a syringe and then draws titrant into the syringe until the endpoint of the reaction is reached. However, the equipment required in this approach is expensive, and the added accuracy and precision unnecessary.
Against this backdrop the present invention has been developed.